Method for the integration of monolithic thin film radiation detector systems

Abstract

A thin film radiation detection device includes a photosensitive p-n diode, a polysilicon thin film transistor (TFT), a radiation detection layer, and a substrate. The photosensitive p-n diode and the TFT are formed on the substrate. The radiation detection layer is formed above the substrate and receives multiple radiations. The photosensitive p-n diode receives a conversion output signal from the radiation detection layer and generates a detector signal. The TFT generates an amplified signal based on the detector signal.

What is claimed is: 
     
       1. A radiation detection device, comprising:
 a first portion of a first polysilicon layer formed on a substrate, wherein the first portion of the first polysilicon layer is a cathode; 
 an n-type layer formed on the first portion of the first polysilicon layer; 
 a p-type layer formed on the n-type layer; 
 a metal layer formed on the p-type layer, wherein the metal layer is an anode, and wherein the n-type and p-type layers, the cathode, and the anode form a photosensitive diode; 
 a second polysilicon layer formed on the substrate, wherein the second polysilicon layer is an active polysilicon island; 
 
       a second portion of the first polysilicon layer formed above the second polysilicon layer, wherein the second portion of the first polysilicon layer is a gate electrode;
 a first layer formed on a first region of the second polysilicon layer, wherein the first layer is a source electrode; 
 a second layer formed on a second region of the second polysilicon layer, wherein the second layer is a drain electrode, and wherein the active polysilicon island, and the gate, source, and drain electrodes form a transistor; and 
 a radiation detection layer formed above the substrate, wherein the radiation detection layer is configured to receive a plurality of radiations and generate a conversion output signal, wherein the photosensitive diode is configured to receive the conversion output signal and generate a detector signal, and wherein the transistor is configured to receive the detector signal and generate an amplified signal. 
 
     
     
       2. The radiation detection device according to  claim 1 , wherein the substrate includes at least one of polyethylene naphthalate, polyethylene terephthalate, a flexible aluminum foil, a flexible stainless steel sheet, and flexible glass. 
     
     
       3. The radiation detection device of  claim 1 , wherein the n-type layer includes cadmium sulfide. 
     
     
       4. The radiation detection device of  claim 1 , wherein the p-type layer includes cadmium telluride. 
     
     
       5. The radiation detection device of  claim 1 , wherein the radiation detection layer includes at least one of a scintillation layer and a neutron conversion layer. 
     
     
       6. The radiation detection device of  claim 1 , wherein the transistor is a thin film transistor. 
     
     
       7. A method for fabricating a radiation detection device, the method comprising:
 forming a first portion of a first polysilicon layer on a substrate, wherein the first portion of the first polysilicon layer is a cathode; 
 forming an n-type layer on the first portion of the first polysilicon layer; 
 
       forming a p-type layer on the n-type layer; 
       forming a metal layer on the p-type layer, wherein the metal layer is an anode, and wherein the p-type and n-type layers, the anode, and the cathode form a photosensitive diode; 
       forming a second polysilicon layer on the substrate, wherein the second polysilicon layer is an active polysilicon island; 
       forming a second portion of the first polysilicon layer above the second polysilicon layer, wherein the second portion of the first polysilicon layer is a gate electrode; 
       forming a first layer on a first region of the second polysilicon layer, wherein the first layer is a source electrode; 
       forming a second layer on a second region of the second polysilicon layer, wherein the second layer is a drain electrode, and wherein the active polysilicon island, and the gate, source, and drain electrodes form a transistor; and 
       forming a radiation detection layer above the substrate, wherein the radiation detection layer receives a plurality of radiations and generates a conversion output signal, wherein the photosensitive diode receives the conversion output signal and generates a detector signal, and wherein the transistor receives the detector signal and generates an amplified signal. 
     
     
       8. The method of  claim 7 , wherein the substrate includes at least one of polyethylene naphthalate, polyethylene terephthalate, a flexible aluminum foil, a flexible stainless steel sheet, and flexible glass. 
     
     
       9. The method of  claim 7 , wherein the n-type layer includes cadmium sulfide. 
     
     
       10. The method of  claim 7 , wherein the p-type layer includes cadmium telluride. 
     
     
       11. The method of  claim 7 , wherein the radiation detection layer includes at least one of a scintillation layer and a neutron conversion layer. 
     
     
       12. The method of  claim 7 , wherein the transistor is a thin film transistor. 
     
     
       13. The radiation detection device of  claim 2 , wherein the n-type layer includes cadmium sulfide. 
     
     
       14. The radiation detection device of  claim 13 , wherein the p-type layer includes cadmium telluride. 
     
     
       15. The radiation detection device of  claim 14 , wherein the radiation detection layer includes at least one of a scintillation layer and a neutron conversion layer. 
     
     
       16. The radiation detection device of  claim 15 , wherein the transistor is a thin film transistor. 
     
     
       17. The method of  claim 8 , wherein the n-type layer includes cadmium sulfide. 
     
     
       18. The method of  claim 17 , wherein the p-type layer includes cadmium telluride. 
     
     
       19. The method of  claim 18 , wherein the radiation detection layer includes at least one of a scintillation layer and a neutron conversion layer. 
     
     
       20. The method of  claim 19 , wherein the transistor is a thin film transistor.